A known comminution machine is disclosed in German Patent DE 103 33 359 B3, wherein the synchronous motor is connected directly to the rotor shaft in a rotationally positive manner.
Owing to the electronic rotational-speed control of the rotor, the known comminution machine can be easily adapted to a variety of comminution conditions, such as those occurring in normal comminution material. It can operate with, on the one hand, a high torque, and, on the other hand, a high rotational speed.
When the known comminution machine is operating at low rotational speeds, in particular when it is working almost at a standstill against a very hard object in the comminution material, it requires a very large amount electric power. Correspondingly, powerful power-supply installations capable of providing some thousand A are available only at those locations where such an electric power consumption has already been allowed for at the planning stage.
Nowadays, however, comminution machines are increasingly being used at various locations for the purpose of breaking down waste into fragments that can then be conveyed as quasi-homogeneous material, possibly made into briquettes, transported, and processed further. Often, such locations do not have a powerful power-supply connection.
The present invention is provided to solve these and other problems.